I didnt return to this because its minor and I didn't want to burden Steve with trivia but yes the small refuel system seems to prevent using a standard refuel system if they are both on the same ship. Which cannot help gameplay and only occurred due to testing in a state of confusion about rules.
why would you put both types of refueling on a ship? the big one refuels all ships and the small one just fighters. there is no need to have both on a single platform
Not everyone knows how the refueling systems work, especially the first time they play. People experiment by building ships and seeing if they work, and often that gets confusing. It is especially problematic to figure out why the refueling orders don’t show up, since there is even less information to go on in that case. Note for example that every so often someone asks if putting two refueling systems on the same craft lets them refuel two ships at a time. Sadly, it does not, so I say that there should be a design warning in that case.
Personally I recommend changing the name to “Small-craft refueling system”, to emphasize that it is _for refueling small craft_ rather than just that it _is small_.
Currently if you put one on a ship larger than 1000t you get this design warning: “Small Craft Refuelling System can only be used on ships of 1000 tons or less”. Since that includes only part of the information, I recommend extending it to say “Small-Craft Refueling System can only be used by small ships of 1000 tons or less to refuel small ships of 1000 tons or less.” (Note also the typo.)
There also should be a design warning if you select the Tanker checkbox but forget to put a refueling system; that’s also a common error. I’m sure it’s been suggested before too. Same with cargo ships that don’t have cargo shuttles, a warning there would go a long way to preventing that very common error. But I am starting to get off–topic.